PB NO
Normally open pushbutton
A pushbutton contact normally shown open before actuation.
Schematic
Symbols · PB NC HOLD
Maintained normally-closed pushbutton
A maintained NC pushbutton retains its actuated open state until the documented return action.
Schematic · PB NC HOLD
What it represents
A maintained NC pushbutton retains its actuated open state until the documented return action. This affects permissive and stopping circuits that depend on contact continuity.
How to read it
- Determine how the operator returns to the reference position.
- The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation.
Information to show or reference
- Label retained state
- Show contact terminal numbers
- Reference return mechanism
A distinction that matters
Maintained NC operation does not alone establish an emergency-stop safety function.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
AutoCAD Electrical: Illuminated push buttons
Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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